The present invention relates to a magnetic particle separating device.
In general, the longer the period of operation of a liquid handling system such as a hydraulic, lubrication or cooling system becomes, the higher the contents of magnetic particles, which result from the corrosion and wear of the system components and are entrained in the liquid, become. As a result, in order to limit the quantities of magnetic particles less than a predetermined tolerance level, they must be periodically separated and removed from the liquid by a suitable device.
In this specification, the magnetic particle separating device of the present invention will be described in conjunction with the separation of radioactive CRUD (Canadian Reactor Unknown Deposits) particles entrained in the primary and secondary coolants in a reactor cooling system.
During the operation of the reactor, the coolants inevitably entrain CRUD particles from a steel pressure vessel, heat exchangers, fuel rods, pipes and so on. CRUD particles consist of magnetitic (Fe.sub.3 O.sub.4), maghemitic (gamma-Fe.sub.2 O.sub.3) and hematitic (alpha-Fe.sub.2 O.sub.3) particles. So far, because of a relatively short history of reactor operation, the separation and removal of CRUD particles from the coolants has not been made. However, it is quite apparent that the longer the period of reactor operation becomes, the higher the quantities of CRUD particles entrained in the coolants become. In addition, CRUD particles are contaminated or radioactive, having an extremely higher degree of space dose. It follows therefore that the separation and removal of CRUD particles from the coolant can obviously reduce the chance of the reactor operators being exposed to the radioactive contaminants in the case of periodical inspection and maintenance and repairs of reactor components. In addition, rediation in a reactor plant can be considerably suppressed and the reuse of water coolant becomes possible.
It is therefore a primary object of the present invention to provide a magnetic particle separating device which can positively separate and remove CRUD particles from the coolants circulated through a reactor cooling system, thereby ensuring the more safeguarded operation of a reactor plant.
The present invention will become more apparent from the description of some preferred embodiments thereof taken in conjunction with the accompanying drawings.